Is the Risk of Developing a Crohn’s Disease Increased after Appendectomy? A Systematic Review of the Literature and Meta-Analysis
Bibliographic record
Abstract
INTRODUCTION: The effect of appendectomy on the development of Crohn's disease (CD) is a matter of debate. The aim of this systematic review and meta-analysis was to gather the latest published data to determine whether patients with a history of appendectomy have an increased risk of developing CD or not. METHODS: MEDLINE, Embase, and the Cochrane Central Register of Controlled Trials were searched for case-control and cohort studies assessing the risk of developing CD after appendectomy. The pooled adjusted and not adjusted odds ratio (OR) with 95% confidence intervals (CIs) were calculated for case-control studies. Heterogeneity was assessed. Studies were ranked using the Newcastle-Ottawa Scale (NOS) and were all of good quality. RESULTS: Fourteen case-control studies and 6 cohort studies were included. Meta-analysis of case-control studies (33,243 patients) of raw OR shows a positive association between appendectomy and CD (OR: 1.51, 95% CI: 0.97-2.36, I2 = 87%), which was not statistically significant (p = 0.069). The meta-analysis of adjusted OR shows that appendectomy represents a statistically significant risk factor for the development of CD (OR: 1.86, 95% CI: 1.01-3.45, p = 0.047, I2 = 89%). CONCLUSION: Appendectomy appears to be a risk factor for the development of CD. However, the discrepant results obtained by meta-analysis of unadjusted OR, the heterogeneity between studies, and the lack of precision of the magnitude of the association mandate confirmation by a large epidemiological study.
Fetched live from OpenAlex and de-inverted. Abstracts are not stored in this database: the inverted indexes are 8.6 GB of the frame’s 9.3 GB of text, and the host has 13 GB free.
How this classification was reachedexpand
Full frame machine prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. The Gemma side is a direct model label for every work in the frame, read from the title-only record. The Codex side is a classifier learned from the 10,348 direct Codex labels and calibrated to design-weighted sample rates; fields without enough sample support carry no Codex call. Candidate is the union of the two sides; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels.
Distilled classifier scores by category (both heads)
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.020 | 0.049 |
| Meta-epidemiology (narrow) | 0.003 | 0.002 |
| Meta-epidemiology (broad) | 0.025 | 0.041 |
| Bibliometrics | 0.009 | 0.010 |
| Science and technology studies | 0.001 | 0.001 |
| Scholarly communication | 0.004 | 0.002 |
| Open science | 0.002 | 0.001 |
| Research integrity | 0.003 | 0.002 |
| Insufficient payload (model declined to judge) | 0.003 | 0.000 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; a candidate call from one source (direct Gemma or distilled Codex), not a consensus.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".